Collagen, a widely used dietary supplement, may help reduce weight in individuals with overweight or obesity, according to a Spanish study presented at the 32nd European Congress on Obesity in Malaga, Spain, and published concurrently in Nutrients.

In the trial, researchers delivered the protein in a chocolate bar consumed with a glass of water 45 minutes before meals. Collagen is well known for its benefits related to bone, joint, and skin aging; however, when its structure is modified to absorb large amounts of water, it may induce satiety and offer a potential appetite-suppressant approach for individuals with overweight or obesity.

“Many weight-loss drugs are very expensive. We were interested in collagen because it is a protein that is inexpensive and easy to obtain and is not known to have any side effects. It is also a compound that the public is familiar with,” said Paola Mercedes Mogna Peláez, researcher at the University of Navarra in Pamplona, Spain.

“Furthermore, the structure of collagen can be modified to absorb more water. We wanted to know if such a compound creates a feeling of fullness when it expands in the stomach, reducing appetite and leading to weight loss,” she said.

The researchers used modified bovine collagen with a very high hydration capacity that expanded nearly 20-fold in acidic stomach pH.

This collagen formulation was incorporated into chocolate bars containing 10 g per serving and tested over 3 months in 64 adults with overweight or obesity.

All participants received healthy eating advice based on the principles of the Mediterranean diet. The intervention group was instructed to consume two chocolate-flavored protein bars enriched with modified collagen, one before lunch and one before dinner.

Participants consumed one bar with a 250 mL glass of water 45 minutes before lunch and dinner and received nutritional counselling.

Each bar contained 10 g of collagen, providing a total daily intake of 20 g of collagen. The control group received the same dietary advice but did not receive collagen-enriched bars.

The participants filled in an appetite questionnaire and underwent a range of body measurements and other tests at baseline and periodically thereafter.

After 3 months, individuals in the collagen vs control group lost more weight, averaging 3 kg vs 2 kg, or 3.36% vs 1.80% of body weight, and also showed greater reductions in blood pressure, liver fat content, and waist circumference.

These differences appeared to be related to the intervention as both groups consumed similar calories during the trial.

The questionnaire showed that the collagen group felt less hungry and fuller than the control group. Levels of leptin, a hormone that induces feelings of satiety, decreased in both groups but were higher at the end of the study in the collagen group than in the control group.

In rats, collagen intake significantly reduced blood ghrelin levels 5 hours after consumption of the collagen supplement.

The supplement also swelled to almost 20 times its original size in stomach acid and had low digestibility.

“Inducing satiety is a strategy that could help individuals with overweight or obesity control their appetite and reduce calorie intake. One possible approach is the ingestion of fibrous molecules that can increase in volume by retaining water,” the investigators said.

According to the authors, further research is needed to determine whether the observed weight loss was directly linked to a decrease in appetite or other mechanisms related to the intestinal microbiota or the actions of collagen-derived bioactive peptides.

The Centre for Nutrition Research in Spain received funding from Viscofan SA, which supplied the collagen supplement and the protein bars, and some of the authors are employed by Viscofan SA. 

This story was translated from MediQuality.